Chris Teutsch: Frost Seeding Clover: Getting it Right

Frost Seeding Clover: Getting it Right!

Chris Teutsch Univerity of Kentucky Grain and Forage Center of Excellence, Princeton, Kentucky

In last month’s article I discussed the important role that legumes play in sustainable grassland ecosystems. This is especially true at current fertilizer prices. Since last month, nitrogen prices have continued to increase (Figure 1). Currently, one pound of nitrogen as urea is coming in at $0.95. In this month’s article I want to provide some practical suggestions for establishing and maintaining legumes in your pastures.

Tips for Getting Clover into Pastures

Soil test and adjust fertility. In order for clover and other improved legumes to persist and thrive in pastures, we must create an environment conducive to their growth. This starts with soil fertility. Prior to frost seeding clover, lime and fertilize pastures according to soil test recommendations. Suppress sod and decrease residue. The existing sod must be suppressed and plant residue reduced prior to frost seeding. The reduction in plant residue allows seed to reach the soil surface where it can be incorporated by freezing and thawing events. Sod suppression and residue reduction is best accomplished by hard grazing in late fall and early winter. Ensure good soil-seed contact. Good soil-seed contact is required for seed germination and emergence. In frost seedings, this occurs when freezing and thawing cycles form cracks in the soil surface, often referred to as a honeycomb. Seed on Proper Date. Frost seeding is best accomplished in late winter or very early spring (February and early March). Frost seeding is accomplished by simply broadcasting the seed on the soil surface and allowing the freezing and thawing cycles to incorporate the seed into the soil. Success with frost seeding can be enhanced by dragging your pasture as, or immediately after, you broadcast the seed. Use High-Quality Seed and Adapted Varieties. Use either certified or proprietary seed to ensure high germination, seed genetics, and low noxious weed content. Do NOT use VNS or Variety Not Stated seed since there is no way to tell how it will perform in Kentucky. Choose clover varieties that have been tested in Kentucky. The University of Kentucky has one of the most extensive variety testing programs in the country. The 2021 variety testing results can be found on the UK Forage Extension website or by visiting your local extension office. Use correct seeding rate. In Kentucky, a good mixture for frost seeding is 6-8 lb/A of red clover, 1-2 lb/A of ladino or grazing white clover. On rented farms or where soil fertility is marginal, adding 10-15 lb/A of annual lespedeza to this mixture can be beneficial. Calibrate seeding equipment. Maintain and calibrate seeding equipment prior to seeding. Several approaches to calibrating small spinner seeders can be viewed on the KYForages YouTube Channel at https://youtu.be/E0wSBYlJDbw. Inoculate Legume Seed. Most improved clover seed comes with a clay-based coating that contains inoculant. Make sure that the seed is fresh and has not been stored under adverse conditions. If the seed is not pre-inoculated, inoculate it with the proper strain of nitrogen fixing bacteria prior to seeding. This is relatively inexpensive insurance that legume roots will be well nodulated and efficient nitrogen fixation will take place. Control Seeding Depth. Small-seeded forages should never be placed deeper than ½ inch. If using a drill always check seeding depth since it will vary with seedbed condition and soil moisture status. Placing small-seeded forages too deep will universally result in stand failures. Since frost seeding broadcasts the seed on top of the soil, this problem is minimized. Check seed distribution pattern. When using a spinner type spreader/seeder make sure and check you spreading pattern. In many cases small-seeded forages are not thrown as far as you think. This can result is strips of clover in your pastures rather than a uniform stand. Use GPS guidance to eliminate overlaps and misses. A recent study conducted at UK Research and Education Center in Princeton found that frost seeding without GPS Guidance resulted in a 35% overlap. Using GPS guidance reduced the overlap to 3%. At an overlap of 20% and an overseeding cost of $30/A, a portable GPS unit will pay for itself in less than 250 acres.

Figure 1. Nitrogen price trends over the last 12 months. Data are from DTN and available at https://www.dtnpf.com/agriculture/web/ag/crops/article/2021/12/08/ nitrogen-fertilizers-lead-pack-start

Control Post-Seeding Competition. Not controlling post-seeding competition is one of the most common causes of stand failures. One of the best management practices is to leave cattle on pastures that have been overseeded with clover until the clover seedlings get tall enough to get grazed off. Then remove animals from the pasture and allow that clover to reach a height of 6-8 inches. At that time the paddock can be placed back into the rotation. If the existing vegetation is not controlled, the new clover seedlings will be shaded out.

Tips for Maintaining Clover into Pastures

Maintain adequate phosphorus and potassium. Maintain soil test levels of P and K in the MEDIUM soil test range or higher. This is best accomplished by routine soil testing. Maintain soil pH above 6.0. The ideal pH for mixtures of coolseason grasses and legumes is 6.0 to 6.4. Regular soil testing and adding lime when needed, will create an environment in which legumes can thrive. Implement rotational stocking. A summary studies comparing rotational and continuous stocking shows that implementation of rotational stocking increases pasture productivity by 30%. In addition to increased productivity, rotational stocking can also be used as a tool to manage botanical composition of pastures. Manage grazing to favor legumes. How we manage grazing can impact the proportion of legumes in stands. Grazing a little bit closer with rest between grazing events puts grasses at a disadvantage since they are dependent on both leaf area remaining after grazing and stored energy for regrowth (Figure 3). This allows legumes to be more competitive in mixed stands. Frost seed legumes on a regular basis. Red clover is a short-lived perennial in pastures and hayfields. In most cases, improved red clover varieties will persist for 2-3 years. Overseeding pastures every year or every other year at a lower seeding rate may result in more consistent stands of legumes in pastures.

Figure 2. Using GPS guidance reduces overlaps and misses. Small portable GPS units like the one below can be transferred between implements and used for spreading fertilizer, litter, and lime or spraying pastures Figure 3. A closer grazing height with rest between grazing events favors legumes, while a higher grazing height favors grasses. This diagram was adapted from ForageAnimal Management Systems by Roy E. Blaser and Colleagues, VAES, Bulletin 86-7 This month’s FEATURED EVENT is 2021 VIRTUAL Alfalfa and Stored Forage Conference in Bowling Green on February 24 at the Warren County Extension Office. More information at https://forages.ca.uky.edu/ and clicking on “UPCOMING EVENTS”.

This month’s FEATURED VIDEO is: is Bale grazing:

challenges, opportunities, and tips for getting it right

by Greg Halich. This presentation was given as part of the 2021 Kentucky Forage and Grassland Council Fall Grazing Conference, "Sustainable Intensification of of Pasture Management in the Mid-South". This conference was held on October 26, 27, and 28 in Princeton, Elizabethtown, and Winchester, KY, respectively. Proceedings of this conference can be found at https://uknowledge.uky.edu/ky_grazing/.

This month’s FEATURED PUBLICATION is AGR-26 Renovating Hay and Pasture Fields” by G.D. Lacefield and S.R. Smith. It can be accessed at https://forages.ca.uky. edu/files/agr26.pdf or by visiting your local extension office.

FENCING TIP

Selecting an energizer. Energizers are the heart of electric fencing systems and are NOT a component that you should try to “save” money on. A low-cost energizer often costs more in terms of future repairs and replacements. If electrical service is available, plug-in energizers are considerably more powerful and offer the best value in terms of cost to power ratio. For remote areas, solar or battery powered energizers are viable alternatives for smaller acreages. Power comparisons of energizers should be done using “stored energy” which is measured in joules.

FORAGE MANAGEMENT TIPS

• Remove animals from wet pastures to limit pugging and soil compaction. • Feed best quality hay to livestock groups with the highest nutritional requirements. Supplement poor quality hay as needed. • Feed hay on your poorest pastures to improve soil fertility and organic matter. • Move feeding points around the pasture to improve nutrient distribution. • Consider bale grazing to improve nutrient distribution. See this month’s featured video. • Buy clover seed early since supplies will likely be tight this spring. Store seed in a cool dry place until frost seeding begins in February. • Inspect and repair seeding equipment. • Consider purchasing a GPS guidance system for improving your frost seeding precision.